A36.81 vs I43
A36.81 (Diphtheritic cardiomyopathy) compared with I43 (Cardiomyopathy in diseases classified elsewhere), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I43 carries an Excludes1 note covering A36.81: “diphtheria (A36.81)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| A36.81Diphtheritic cardiomyopathy | I43Cardiomyopathy in diseases classified elsewhere | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | I00-I99 — Diseases of the Circulatory System (I00-I99) |
| Definition | Diphtheritic cardiomyopathy is a billable ICD-10-CM diagnosis code (A36.81). | Cardiomyopathy in diseases classified elsewhere is a billable ICD-10-CM diagnosis code (I43). |
| Includes | Diphtheritic myocarditis | — |
| Code first | — | underlying disease, such as: amyloidosis (E85.-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources